Gun operation signal mechanism



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May 16, 1944. R, N. LESNICK 2,349,182

GUN OPERATION SIGNAL MEJHANISM Filed May 14, 1941 aux/v so: .nvo/a l insBELT

lNVENIOR Robert NLesmck, M VQM.

ATTORN EY5 Patented May 16, 1944 2,349,182" p q GUN OPERATION SIGNALMECHANISM Robert N. Lesnick, Brooklyn, N. Y. assignor to BrewsterAeronautical Corporation, Long Island City, N. Y.

Application May' 14, 1941,

4 Claims.

This invention relates to automatic guns, and more particularly tooperation indicator devices for use in connection with machine gunsmounted upon aircraft and. the like.

In machine gun installations in aircraft, and the like, each gun isusually provided with an associated cartridge magazine out of which acartridge belt, comprising a row of axially parallel cartridges Withsuitable linking elements, moves continuously for feeding the machinegun in response to actuation of the feed pawl mechanism of the gun. Thecartridge belt is usually trained about rollers or star wheels fordirectional changes during the movement from the magazine to the gun;such rollers or star wheels being mounted for idling rotation as aresult of their engagement with the moving cartridge belt. According tomy present invention I utilize the rotation of such star wheel, or othermoving elements of the machine gun installation, to continually make andbreak anelectric circuit, including means adapted to produce in animproved manner an indication of the condition of operation of themachine gun associated therewith.

In setting forthan exemplary embodiment of my invention. reference willbe had to the accompanying drawing whichis a diagrammatic representationof the circuits and electrical and mechanical devices. cooperating toprovide an aerial machine gun operation indicator mechanism of theinvention. In the drawing the numerals 9 and I indicate schematically amachine gun and a cartridge magazine therefor, respectively. .Aseries ofcartridges II are illustrated as being-linked together in the form of acartridge belt l2 arranged to move from the cartridge magazine into themachine gun. A star wheel I3 is arranged upon a supporting shaft l4, andis provided with arcuate peripheral indentations as at I5 forintermeshing engagement with individual cartridges II as they movetoward the gun in response, to the cartridge belt feeding operation ofthegun feed pawl mecha-. nism (not shown).

. It will be understood that in military aircraft a plurality of machineguns are usually employed, and that in such installations the individualguns are usually each provided with an operating relay or solenoid suchas is indicated. at 18 in the drawing. For example, a typical solenoidarrangement for .this purpose isdisclosed at 35, Figs. 2 and 4 of U. '8.Patent 2,180,751. An operating circuit for each gun solenoid |8 maycomprise a battery l9 and aconductor connectin Serial No. 393,373).

one terminal of the battery with one terminal of the gun solenoid. Theremaining terminals of the battery and of the gun operating solenoid l8are grounded to complete the gun operating circuit, as indicated in thedrawing at 22 and at 23, respectively. 1 7

Thus, as many. gun solenoids are providedas there are machine guns, andpreferably each gun solenoid circuit has interposed therein a snapselector switch 24.- Obviously the portion of the operating circuitwhich leads from the battery ground 22 through the battery and to oneterminal of the selector switch 24 may be common to a. number 0f.machineguns. The portion of the operating circuit leading from the selectorswitch 2-! to thegun operating solenoid l8 and therethrough to theground 23 will, however, be duplicated for each machine gun; there beinga selector switch for each gun operating solenoid I8. v I

Interposed in the portion of the conductor 20 which is common to all ofthe machine gun operating circuits, is a manually closable switch knownas a trigger switch, such as is indicated at 25 in the drawing. Suchtrigger switch is usually provided with an operating button 26 which ispreferably placed in a position of extreme convenience to the gunner,and in the case of a single seater combat airplane it is usually mountedon the upper end of the control stick thereof. Thus, whenever the gunnerdepresses the button 26 the trigger switch 25 is closed, and as manyguns will be caused to fire as have their associated selector switches24 closed.

In the embodiment now being set forth it is intended to provide anindividual indicating or warning device for each machine gun and to thisend a warning lamp 28 may be arranged within easy view of the machinegun operator. Disposition of each lamp 28 in close association with itsassociated selector switch 24 will render identification of theindicating or warning lamps of the several machine guns 2. simplematter.

In the form of my invention illustrated in the drawing I provide acircuit for each lamp 28 which is provided with a switch adapted to bebiased to a. closed position for rendering a warning signal, but suchswitch in normal operation is held open against the biasing tendency'bynormal movement of cartridges from the magazine to the gun to render thelamp inoperative excepting when the impulse which normally holds thebiased switch open fails.

The lamp circuit for each gun installation comprises a conductor 30which taps the gun circuit energized. Attraction of the armature 33 bythe I electromagnet 34 opens the switch 32 against its biasing means.

It will presently appear that the electromagnet 34 is arranged in theelectrical circuit in such fashion as to be energized during continuedproper movement of cartridges II from the cartridge magazine In to themachine gun 9 when the trigger switch 26 and any one or more selectorswitches 24 associated with particular lamps 28 are closed; However,stoppage of cartridge passage from the associated cartridge magazine toa particular machine gun will result in cessation of rotation of theassociated star wheel I3, and, in a manner which will presently appear,such stoppage of the star wheel I3 results in deenergization of theelectromagnet 34 despite continued closure of the gun operating circuit.

A two-way switch 40 is arranged to be automatically alternated betweenits two circuit closing positions by means of an oscillating arm 4!which is adaptedto be oscillated by contact between a roller 42' carriedat one of its ends with a cam Wheel 43 which is fixed for rotation withthe star wheel I3. The other end of the oscillati'ng arm 41 is pivotallysupported as at 45. It isto be understood that the normal speed ofoperation of the associated machine gun and'the plurality of notchesappearing in the cam wheel 43 are such that a rapid alternation of theswitch 40 between its two circuit closing positions will take place aslong as the cartridge belt moves over the star wheel I3 toward thecartridge feedway of the gun.

When the switch ib-is in a position opposite to that shown in thedrawing a circuit is closed which includes a conductor 50 which taps themain gun circuit 20 between the selector switch 24 and the ground 23 andleads to the upper con tact of the switch 40, and then through theswitch bar and over a conductor 54 to one terminal of the electromagnet34. The conductor 54 includes a condenser 56; The opposite ter-- minalof the electromagnet 3k is grounded as at 5'! via a conductor 58.

It will be seen that in its upper position the switch 45 establishes acircuit which loads the condenser 55. If we consider 'thegrounded sideof the batter as negative, then the right-hand plate of the condenser 56will be positively charged and the left-hand plate, as viewed in thedrawing, negatively charged.

Upon. reversal of the switch 40 to the position shown in the drawing,the circuit 25, 50, 54,- 58 is broken between conductors 50 and 54 andsubst'antially concurrently therewith the switch arm 40 engages thelower contact 50 of the two-way switch, lower contact 56 being connecteddirectly to ground as by means of a conductor BI.

With the switch arm 40 in this position, that is as shown in thedrawing, the conductor 54, including the condenser '53 and theelectromagnet 34, is connected directly to ground at both ends; at oneend permanently by the conductor 58 and at. itsother endi throughttheswitch arm 41], the

contact 60, and the conductor 6|. When the arm of the switch 40 is inengagement with the contact 60 as here set forth the conductor 6I shortcircuits the electromagnet 34 and the condenser 56 which is in seriestherewith and the condenser releases its charge, causing reverse currentflow in the circuit until the condenser is unloaded.

Thus, normal operation of the starwheel provides successive andalternate charging and discharging of the condenser 56 at a rapid rate,resulting in a substantially continuous alternating current excitationof the electromagnet 34 with I consequent attraction of the armature 33with the result that switch 32 is held in open position while the. armof the switch 40 is alternating between the contacts 51 and 60.

Cessation of rotation of the star wheel I3 results in de-energization ofthe electromagnet 34 regardless of the particular position of the switcharm II] at the time of discontinuance of operation of the star wheel I3and its associated instrumentalities and despite continued closure'ofthe gun solenoid operating circuit. I

If the switch arm 40 happens to be in the position illustrated in thedrawing when the star wheel stops, the electromagnet 34 will bedeenergized as soon as the condenser unloads by. virtue .cf the opencircuit at 5I.. If the switch arm fiflhappens to be in an oppositeposition at the timeof stoppage, current will flow in the clrcuitti i,56,34, 58, only instantaneously, until the condenser 56 is fullycharged, and thecon- 'tinued application of. direct current to thecircuit will beineffective due to the presence of the condenser 55.

From the foregoing it will be seen that continued rapid alternation. ofthe position of the switch 40- by: rotation of. the starv wheel I3provides a holding impulse by way of the electromagnet 34 whichkeepssthelamp circuit 30 open through the medium of the switch 32. As-soon as thestar wheel. I3 discontinues rotation, the electromagnet 34.. becomesde-energized and the switch 32 closes under the force of gravity orwhatever other biasing means, inthe form of a spring or the like, isemployed. Closure of the lamp circuit 30 illuminates the lamp 28 andapprises the. operator of the machine gun of the stoppage of the starwheel I3. Consequently, if the associated machine gun jams, or if thecartridge belt runs out, or if the operation of feeding. the. machinegun stops for any reason. whatsoever, the consequent stoppage ofrotation of the star wheel I3 automatically resultsin illumination ofthe signal lamp 28; proid'ed' the corresponding selector switch 24 andthe trigger switch 25 are also closed. Hence, the operator of themultiple gununit is immediately apprised of. unintended stoppage ofthe'firing operation of any one or more of the guns of the unitso thathemay be directed to the cause of .redu'cedfire, in an improved manner.

While a single complete embodiment of the principles of my invention isdisclosed herein by way of example, it is to be understood'that myinvention is'not-to be considered as limited there'- to or otherwisethan as defined in the appended claims.

What -is claimed is:

1. Cessation indicating means for a normally movable member having adirect current operating circuit and motive meanstherein for moving saidmember, said indicating means comprising a. lamp ilnsaid circuit inparallel with said motive means, a normally closed switch in said lampcircuit and an electromagnet for opening said switch, said electromagnetbeing connected in parallel with said motive means and said lamp, aswitch and a condenser connected in series with said electromagnet, aground connection engageable by said switch when the latter is open, andmeans operated by said movable member for continuously opening andclosing said switch during movement of said movable member whereby thecondenser is successively loaded and discharged to provide alternatingcurrent energization of said electromagnet while said movable member isoperating, whereb said lamp is illuminated only when said direct currentoperating circuit is closed and said movable member is not moving.

2. Cessation indicating means for a normally movable member having adirect current operating circuit and motive means therein for movingsaid member, said indicating means comprising a lamp in said circuit inparallel with said motive means, a normally closed switch in said lampcircuit and an electromagnet for opening said switch, said electromagnetbeing connected in parallel with said motive means and said lamp, aswitch and a condenser connected in series with said electromagnet, andmeans operated by said movable member for continuously opening andclosing said switch during movement of said movable member to providecontinuous alternating current energization of said electromagnet whilesaid movable member is operating, whereby said lamp is illuminated onlywhen said direct current operating circuit is closed and said movablemember is not moving.

3. Cessation indicating means for a rotatable member having a directcurrent operating circuit and motive means therein for rotating saidmember, said indicating means comprising a lamp in said circuit inparallel with said motive means, a normally closed switch in said lampcircuit and an electromagnet for opening said switch, said clectromagnetbeing connected in parallel with said motive means and said lamp, aswitch and a condenser connected in series with said electromagnet, andmeans operated by said rotatable member for continuously opening andclosing said switch during movement of said rotatable member to providecontinuous alternating current energization of said electromagnet whilesaid rotatable member is operating, whereby said lamp is illuminatedonly when said direct current operating circuit is closed and saidrotatable member is not moving.

4. Cessation indicating means for a normally movable member having adirect current operating circuit and motive means therein for movingsaid member, said indicating means comprising a lamp in said circuit inparallel with said motive means, a normally closed switch in'said lampcircuit and an electromagnet for opening said switch, said electromagnetbeing connected in parallel with said motive means and said lamp, areversing switch and a condenser connected in series with saidelectromagnet, and means operated by said movable member forcontinuously reversing said switch during movement of said movablemember to provide continuous alternating current energization of saidelectromagnet while said movable member is operating, whereby said lampis illuminated only when said direct current operating circuit is closedand said movable member is not moving.

ROBERT N. LESNICK.

